Dear Midas experts,

I noticed that a check was added to mfe.cxx in 1961af0d6:

+      /* check for consistent common settings */
+      if ((eq_info->read_on & RO_STOPPED) &&
+          (eq_info->eq_type == EQ_POLLED ||
+           eq_info->eq_type == EQ_INTERRUPT ||
+           eq_info->eq_type == EQ_MULTITHREAD ||
+           eq_info->eq_type == EQ_USER)) {
+         cm_msg(MERROR, "register_equipment", "Events \"%s\" cannot be read when run is stopped (RO_STOPPED flag)", equipment[idx].name);
+         return 0;
+      }

This commit was by Stefan in May 2022.

A commit few days later, 28d9c96bd, removed the "return 0;", and updated the
error message to:

"Equipment \"%s\" contains RO_STOPPED or RO_ALWAYS. This can lead to undesired side-effect and should be removed."

So such FEs can run but there is still an error at start up. The 
documentation at https://daq00.triumf.ca/MidasWiki/index.php/ReadOn_Flags
states with RO_STOPPED "Readout Occurs" "Before stopping run".
Which seems to indicate that the removing the RO_STOPPED bit from a SC FE
would just result in an additional read not happening just prior to a run
stop. However reading scheduler() in mfe.cxx I see in the the main loop:

 if (run_state == STATE_STOPPED && (eq_info->read_on & RO_STOPPED) == 0) 
    continue;

So it seems to me that the a EQ_PERIODIC equipment needs RO_STOPPED to be set
otherwise it will not read out data while there is no DAQ run.

Can someone explain the purpose of this check and error message? Perhaps it
was put in place with only DAQ FEs, not SC FEs in mind? And should the 
documentation in the wiki actually be "s/Before stopping run/While run is stopped/"?

Thanks,

Nick.